Removes monthly report for versions before 1.3

[NejcZdovc]

Resolves brave/brave-browser#8987

Submitter Checklist:

• Submitted a ticket for my issue if one did not already exist.
• Used Github auto-closing keywords in the commit message.
• Added/updated tests for this change (for new code or code which already has tests).
• Verified that these changes build without errors on
  • Android
  • iOS
  • Linux
  • macOS
  • Windows
• Verified that these changes pass automated tests (unit, browser, security tests) on
  • iOS
  • Linux
  • macOS
  • Windows
• Verified that all lint errors/warnings are resolved (npm run lint)
• Ran git rebase master (if needed).
• Ran git rebase -i to squash commits (if needed).
• Tagged reviewers and labelled the pull request as needed.
• Request a security/privacy review as needed.
• Add appropriate QA labels (QA/Yes or QA/No) to include the closed issue in milestone
• Public documentation has been updated as necessary. For instance:
  • https://github.com/brave/brave-browser/wiki/Deviations-from-Chromium-(features-we-disable-or-remove)
  • https://github.com/brave/brave-browser/wiki/Proxy-redirected-URLs
  • https://github.com/brave/brave-browser/wiki/Fingerprinting-Protections
  • https://github.com/brave/brave-browser/wiki/Brave%E2%80%99s-Use-of-Referral-Codes
  • https://github.com/brave/brave-browser/wiki/Custom-Headers
  • https://github.com/brave/brave-browser/wiki/Web-compatibility-issues-with-tracking-protection
  • https://github.com/brave/brave-browser/wiki/QA-Guide

Test Plan:

• start browser with a profile that has history of rewards before 2020
• open monthly statement
• make sure that you only see Feb 2020 and forward

Reviewer Checklist:

• New files have MPL-2.0 license header.
• Request a security/privacy review as needed.
• Adequate test coverage exists to prevent regressions
• Verify test plan is specified in PR before merging to source

After-merge Checklist:

• The associated issue milestone is set to the smallest version that the
  changes has landed on.
• All relevant documentation has been updated.

[tmancey]

1.3.1 was available from 13th November 2019?

[NejcZdovc]

@tmancey 1.3 was released February 7, 2020. Nightly was Nov 2019

[tmancey]

@tmancey 1.3 was released February 7, 2020. Nightly was Nov 2019

1.3.1 was released to "nightly" in November, however, @NejcZdovc has clarified it was decided that this fix should only consider "release"

[tmancey]

LGTM

[NejcZdovc]

CI failed on a known thing

[LaurenWags]

Verified passed with

Brave	1.9.21 Chromium: 81.0.4044.92 (Official Build) nightly (64-bit)
Revision	32921c79b6f01a0fb2deef0e1d45b42f96581051-refs/branch-heads/4044@{#883}
OS	macOS Version 10.14.6 (Build 18G3020)

Personal profile monthly statement on 1.8.75 (Beta):

Personal profile using 1.9.21 (Nightly)